Viscosities of dispersions of raw and various processed rice flours in water were examined with a coaxial cylinder viscometer. The measured viscosity increased with increasing degree of processing and with a reduced level of apparent starch reassociation in the processed rice. Measurement of the apparent viscosity of cold slurries could thus be a simple practical test of processed, including parboiled, rice and of the degree of processing. The system showed time‐dependent thinning and a typical loop in the shear rate‐viscosity curve, showing that it was thixotropic in nature. The viscosities were proportional to the hydration power and slurry‐sedimentation behaviour of the sa